Control valves are widely used in various mechanical applications, including automotive and industrial applications, especially for variable cam timing applications in internal combustion engines. Existing control valves typically require high manufacturing tolerances for the control valve body. High tolerance valve bodies are relatively complicated and consequently are also expensive to manufacture. Known control valves are disclosed in U.S. Pat. No. 4,637,439, U.S. Pat. No. 5,513,832, and U.S. Pat. No. 6,322,468.
Control valves also typically experience leakage between ports due to ineffective sealing. Leakage of hydraulic fluid between ports on a control valve compromises the control function, ultimately reducing the efficiency or operation of the associated engine element.